Adhesive articles with improved air egress

ABSTRACT

This invention relates to an adhesive article which provides air egress. Air egress is provided by supplying a route, such as areas of no initial adhesion for the air to flow out from under the construction. The invention relates to an adhesive article comprising a facestock having a front surface and a back surface, a continuous layer of adhesive having an upper surface and a lower surface wherein the upper surface of the adhesive layer is adhered to the back surface of the facestock, and a plurality of spaced-apart non-adhesive material which is in contact with the lower surface of the adhesive layer. These articles have usefulness as industrial graphics images, as well as decorative coverings, etc. The articles provide air egress and optionally repositionability and slideability.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a division of U.S. application Ser. No.10/852,878 filed May 25, 2004, which is a division of U.S. applicationSer. No. 09/742,654 filed Dec. 21, 2000, now U.S. Pat. No. 7,060,351issued Jun. 13, 2006, which claims the benefit of U.S. ProvisionalApplication No. 60/199,244 filed Apr. 24, 2000, all of which areincorporated herein by reference in their entireties.

TECHNICAL FIELD OF THE INVENTION

This invention relates to adhesive articles and methods of making thesame. The adhesive articles may be used for graphic images, such asthose used on vehicles.

BACKGROUND OF THE INVENTION

Pressure sensitive adhesives have enjoyed great acceptance for theirconvenience of use. The pressure sensitive adhesive is often used fortapes and articles containing graphic images. The advantages of thepressure sensitive adhesives are their strong bonding and simplicity ofapplication. One drawback of these products is the initial tenacity ofthe pressure sensitive adhesive. The positioning of the product must beprecise because of the initial strong bond of the adhesive. A needexists to make products using pressure sensitive adhesives which arerepositionable, i.e. the product may be removed after light applicationof pressure without destroying the product or the substrate. Anotherneed exists for the products to be able to slide. Slideability allowsfor correction of alignment of the product without the need ofcompletely removing the product and possibly destroying the adhesivearticle or substrate.

When the product is a graphic image and is applied over an area like awall or truck panel, there is the possibility of trapping air under theproduct and forming bubbles or wrinkles. The product must exhibit airegress, i.e. the ability of the product to provide a route for airtrapped under the product to be removed.

A need exists for products which have one or more of the desirableproperties of air egress, repositionability and slideability.

SUMMARY OF THE INVENTION

This invention relates to an adhesive article which provides air egress.Air egress is provided by supplying at least one route, such as areas ofno initial adhesion for the air to flow out from under the construction.The invention relates to an adhesive article comprising a facestockhaving a front surface and a back surface, a continuous layer ofadhesive having an upper surface and a lower surface, wherein the uppersurface of the adhesive layer is adhered to the back surface of thefacestock, and a pattern of non-adhesive material forms that are inembedded into the lower or upper surface of the adhesive layer. Theinvention further relates to methods of preparing the adhesive articles.These articles have usefulness as industrial graphics images, as well asdecorative coverings, etc. The articles provide one or more of airegress, repositionability and slideability.

The method of making the adhesive articles of the present inventionincludes the steps of: (a) applying a pattern of a non-adhesive materialonto an adhesive layer that has been coated onto a facestock; (b)embedding the non-adhesive material into the adhesive layer; andoptionally, (c) applying a release liner to the adhesive layer. Theembedding and applying steps may be combined.

Another embodiment of the method of making the adhesive articles of thepresent invention includes the steps of: (a) applying a pattern of anon-adhesive material onto an adhesive layer that has been coated onto arelease liner; (b) embedding the non-adhesive material into the adhesivelayer; and (c) applying a facestock or a second release layer to theadhesive layer. The embedding and applying steps may be combined.

DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 b are cross sectional areas of an adhesive article withnon-adhesive material embedded in the adhesive.

FIGS. 2 a and 2 b are cross sectional areas of an adhesive article withnon-adhesive material embedded and with a textured finish, such as amatte finish.

FIGS. 3 a, b and c are cross sectional areas of an adhesive article witha non-adhesive material embedded in the adhesive layer at the interfacebetween the adhesive and the facestock.

FIGS. 4 a and 4 b are cross sectional areas of an adhesive article withnon-adhesive material in channels within the adhesive layer.

FIGS. 5 a and 5 b are cross sectional areas of an adhesive article witha porous non-adhesive material embedded in the adhesive layer at theinterface between the adhesive and the release liner.

FIGS. 6 a, b and c are cross sectional areas of an adhesive article witha porous non-adhesive material embedded in the adhesive layer at theinterface between the adhesive and the facestock.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As described above, the present invention relates to adhesive articlessuch as those used for industrial graphics. The adhesive articlesprovide one or more of air egress, repositionability and slideabilityfor easy application to a substrate.

The adhesive articles comprise a facestock, a continuous adhesive layer,and a non-adhesive material. The adhesive article may further comprise arelease liner releasably adhered to the adhesive layer. In oneembodiment, the non-adhesive material includes non-adhesive polymers,including ink compositions applied by printing methods. In anotherembodiment, the non-adhesive material is applied by vacuum metallizationor by sputtering. The non-adhesive material, after drying, cooling,and/or curing, adheres to the upper or lower surface of the adhesivelayer. In one embodiment, the non-adhesive composition contains greaterthan 50%, or greater than 75%, or greater than 85% solids. In anotherembodiment, the non-adhesive composition is 100% solids.

In one embodiment, the non-adhesive material can be any material thatcan be used as the ink on a printing machine, provided that upon drying,cooling, and/or curing, the non-adhesive material is not tacky. Thenon-adhesive material may be made of organic polymeric material such aspolyurethane, polyvinyl chloride, acrylic polymers, acetate,polyethylene, polypropylene or polystyrene and the like.

In one embodiment, the non-adhesive composition is a UV curable ink. Theultraviolet radiation curable inks useful in the invention generallycomprise a binder which comprises one or more photopolymerizablemonomers. The photopolymerizable monomers generally are ethylenicallyunsaturated compounds. The unsaturated compounds may contain one or moreolefinic double bonds, and they may be low molecular weight compounds,(monomeric) or high molecular weight compounds (oligomeric).Illustrative examples of monomers containing one double bond areacrylates such as alkyl(meth)acrylates or hydroxyalkyl(meth)acrylatessuch as methyl-, ethyl-, butyl-, 2-ethyl hexyl- or2-hydroxyethylacrylate, iso bornylacrylate, methyl- orethylmethacrylate. Further examples of photopolymerizable monomers areacrylonitrile, acrylamide, methacrylamide, N-substituted (meth)acrylamides, vinyl esters such as vinyl acetate, vinyl ethers such asisobutylvinyl ether, styrene, alkylstyrenes and halostyrenes,N-vinylpyrrolidone, vinyl chloride or vinylidene chloride.

Monomers containing a plurality of double bonds are typically thediacrylates of ethylene glycol, 1,3-propylene glycol, 1,4-butaneodiol,1,4-cyclohexane diol, neopentyl glycol, hexamethylene glycol, orbisphenol A polyacrylates such as trimethylolpropane triacrylate andpentaerythritol triacrylate or tetraacrylate, vinyl acrylate, divinylbenzene, divinyl succinate, diallyl phthalate, triallylphosphate,triallylisocyanurate or tris(2-acryloyloxy)ethyl-isocyanurate.

Typical examples of high molecular weight (oligomeric) polyunsaturatedcompounds are acrylated epoxy resins, acrylated polyethers, acrylatedpolyurethanes or acrylated polyesters. Further examples of unsaturatedoligomers are unsaturated polyester resins which are normally preparedfrom maleic acid, phthalic acid and one or more diols and which havemolecular weights of about 500 to about 3000. Such unsaturated oligomersmay also be referred to as prepolymers. Single component systems basedon photocurable prepolymers are often used as binders for printing inks.Unsaturated polyester resins are normally used in two-component systemstogether with a monounsaturated monomer such as described above,preferably with styrene.

The unsaturated compounds also can be used in admixture withnon-photopolymerisable film-forming components. These components maytypically be drying polymers or their solutions in organic solvents,such as nitrocellulose. They may also, however, be chemically curable orthermocurable resins such as polyisocyanates, polyepoxides or melamineresins. The concomitant use of thermocurable resins is important for usein so-called hybrid systems which are photopolymerised in a first stepand crosslinked by a thermal after treatment in a second step.

The UV radiation curable inks also should contain at least onephotoinitiator. A wide range of different photoinitiators is at presentavailable for UV radiation curable systems. They include benzophenoneand benzophenone derivatives, benzoin ethers, benzil ketals,dialkoxyacetophenones, hydroxyacetophenones, aminoacetophenones,haloacetophenones or acryloxyphosphine oxides. They differ in that theyhave different absorption maxima. To cover a wide absorption range it ispossible to use a mixture of two or more photoinitiators. The totalamount of photoinitiator in the UV radiation curable compositions may bein the range of from about 0.05 to about 7, or 10% by weight of thetotal composition. Preferably the compositions contain from about 0.2%to about 5% by weight of the photoinitiator.

Amines may be added to accelerate the photopolymerisation, for exampletriethanolamine, N-methyl-diethanolamine, p-dimethylaminobenzoate orMichler's ketone. The photopolymerisation can further be accelerated bythe addition of photosensitisers which displace or broaden the spectralsensitivity. These photosensitisers are preferably aromatic carbonylcompounds such as thioxanthone, anthraquinone and 3-acyl-coumarinderivatives as well as 3-(aroylmethylene)-thiazolines.

Hindered amine light stabilizers (HALS) which function asco-stabilizers, also may be added to the UV radiation curable printingcompositions used in the present invention. Examples of hindered aminelight stabilizers include those listed and recited in U.S. Pat. Nos.5,112,890 and 4,636,408, which are incorporated herein by reference. Aspecific example of a hinder amine light stabilizer useful in theprinting inks is Tinuvin 292 which is identified asbis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate.

In addition to the above described binder materials and photoinitiators,the UV radiation curable inks used in the present invention may alsocontain coloring matter selected from organic pigments, inorganicpigments, body pigments and dyes which are known and have been used inthis art. Examples of useful pigments include titanium dioxide, cadmiumyellow, cadmium red, cadmium maroon, black iron oxide, carbon black,chrome green, gold, silver, aluminum and copper. Examples of dyesinclude alizarine red, Prussian blue, auramin naphthol, malachite green,etc. Generally the concentration of the pigment or dye in the ink willbe from about 0 to about 70% by weight, and in one embodiment, fromabout 0.1% to about 50% by weight.

In addition to the above described coloring matter, the UV radiationcurable inks used in the present invention may also contain fillers,extenders, surfactants, and the like which are known and have been usedin this art. Examples of useful fillers and extenders include silicondioxide, fumed silica, glass or ceramic microspheres, and glass orceramic bubbles. Generally the concentration of the filler or extenderwill be from about 0 to about 70% by weight, and in one embodiment, fromabout 0.5% to about 50% by weight.

The printing inks may also contain at least one UV absorber whichprovides weathering protection and helps prevent microcracking. Theamount of UV absorber included in the UV radiation curable ink should bemaintained at a practical minimum since the presence of the UV absorbermay increase the curing rate. A variety of UV absorbers are known anduseful in the present invention and these include UV absorbers belongingto the group of photopolymerisable hydroxybenzophenones andphotopolymerisable benzotriazoles. U.S. Pat. No. 5,369,140 describes aclass of 2-hydroxyphenyl-s-triazines that are useful as UV absorbers forradiation curable systems. The triazines are effective for stabilizingcured films when exposed to sunlight over a long period of time, andthese stabilizers do not interfere with UV radiation curing of the inks.The triazine UV absorbers are effective in amounts of from about 0.1 toabout 2% by weight. The UV absorbers may be used in combination withother light stabilizers such as sterically hindered amines. Thedisclosure of the '140 patent is hereby incorporated by reference forits disclosure of such UV absorber combinations. U.S. Pat. Nos.5,559,163 and 5,162,390 also describe UV absorbers which are useful inthe inks of the present invention.

Examples of useful UV curable inks include those available from Decochemunder the trade designation Poly-Rad plastics, as well as UV curableinks commercially available from Acheson and Dow Chemical Company.

In one embodiment of the invention, the ink used to form thenon-adhesive material on the adhesive layer is a coalescing ink. The inkdoes not efficiently wet out on the surface of the adhesive, butcoalesces into smaller areas of ink with an increase in height. Thus,depending on the degree of coalescence, a line of printed ink can form anarrower line, or a line made up of what appear to be random small beadsof ink, or a combination, all with an increase in height. The narrowerline, small beads, or combination are then embedded into the adhesive.The thickness of the ink applied to the surface of the adhesive layercan also affect the degree of coalescence. Surfactants may be added tothe ink composition to control the degree of coalescence as well.

In one embodiment of the invention, the ink used to form thenon-adhesive material comprises a porous non-adhesive. The porousnon-adhesive may have elastomeric properties, so that if it iscompressed, it essentially returns to its original shape. For examplethe porous non-adhesive comprises an ink containing a blowing agent thatcauses the ink to expand, forming an open or closed cell, or combinationthereof. The blowing agent is activated, for example, by the applicationof heat to the ink. Other examples of porous non-adhesives includesuspensions of gas and/or particles in a binder. The porous non-adhesiveis then embedded into the adhesive layer. The porous non-adhesive fillsthe depression created in the embedding step, resulting in a facestocklayer having a smooth outer appearance.

The non-adhesive material is generally present in a pattern. The patterncan be a plurality of dots, lines, or any geometric figure, thatprovides a path for air egress from the adhesive article. When lines areused, at least about 50% of the pattern should extend to the edge of theadhesive article to obtain acceptable air egress. The lines and dots mayvary in size provided that air egress is maintained. The lines and otherpatterns generally have an average thickness from about 0.3μ to about100μ, or from about 0.5μ to about 50μ, or from about 2μ to about 20μ.The width of the lines may also vary widely. An example of a usefulrange for line width is from about 12μ to about 250μ, or from about 25μto about 125μ, or from about 50μ to about 75μ. The pattern may be a gridof intersecting lines, a weave pattern, a waffle pattern, diagonalstraight and curved lines, tiled geometric figures, such as hexagons,rectangles, overlapping circles or triangles, or lines in a cross hatchpattern. Combinations of patterns may be used such as a grid ofintersecting lines with random or patterned dots. The non-adhesivematerial may be applied by any means.

In one embodiment, the non-adhesive material is an ink comprising a UVcurable polymer composition, such as a UV curable acrylic orpolyurethane composition. After application, the ink is cured byirradiation in a UV exposure apparatus as is well known to those skilledin the art of printing and UV curing. UV light sources such as lowpressure mercury lamps, high pressure mercury lamps, xenon lamps, arclamps and gallium lamps are useful. It is also possible, but notnecessary, to improve the curability of the ink by heating afterirradiation.

In one embodiment, the non-adhesive material is a polymer compositionwhich is able to be printed by any suitable printing technique such asscreen printing, roller coat printing, flexographic printing,lithographic printing, gravure printing, laser printing, ink jetprinting, brushing, spraying, dipping or coating. The type of printingmay be any type which can print on the pressure sensitive adhesive. Oneparticularly useful printing method is a modification of flexographicprinting which provides both the printing and embedding of thenon-adhesive material.

In one embodiment, the non-adhesive layer is a printing ink having athickness from about 0.3 to about 100 microns, from about 0.5 to about50 microns, or from about 2 to about 20 microns. The non-adhesivematerial may also be applied to the pressure sensitive adhesive by meansof patterned vacuum metallization or sputtering. In this embodiment, thenon-adhesive layer typically has a thickness from about 30 to about3000, from about 100 to about 2000, or from about 300 to about 1500nanometers.

As described above, the adhesive article has a facestock, an adhesivelayer, a plurality of non-adhesive material and optionally theconstruction has a release liner. The facestock may be any of thosewhich are useful for decorative or graphic image applications. Thefacestocks typically have a thickness from about 10 to about 300, orfrom about 25 to about 125 microns. The facestocks include paper,polyolefins (linear or branched), polyamides, polystyrenes, nylon,polyesters, polyester copolymers, polyurethanes, polysulfones,polyvinylchloride, styrene-maleic anhydride copolymers,styrene-acrylonitrile copolymers, ionomers based on sodium or zinc saltsof ethylene methacrylic acid, polymethyl methacrylates, cellulosics,fluoroplastics, acrylic polymers and copolymers, polycarbonates,polyacrylonitriles, and ethylene-vinyl acetate copolymers. Included inthis group are acrylates such as ethylene methacrylic acid, ethylenemethyl acrylate, ethylene acrylic acid and ethylene ethyl acrylate.Also, included in this group are polymers and copolymers of olefinmonomers having, for example, 2 to about 12 carbon atoms, and in oneembodiment 2 to about 8 carbon atoms. These include the polymers ofalpha-olefins having from 2 to about 4 carbon atoms per molecule. Theseinclude polyethylene, polypropylene, poly-1-butene, etc. An example of acopolymer within the above definition is a copolymer of ethylene with1-butene having from about 1 to about 10 weight percent of the 1-butenecomonomer incorporated into the copolymer molecule. The polyethylenesthat are useful have various densities including low, medium and highdensity ranges. The low density range is from about 0.910 to about 0.925g/cm³; the medium density range is from about 0.925 to about 0.940g/cm³; and the high density range is from about 0.94 to about 0.965g/cm³. Films prepared from blends of copolymers or blends of copolymerswith homopolymers also are useful. The films may be extruded as amonolayer film or a multi-layered film.

In one embodiment, the first facestock is a polymeric facestock, whichcontains migratory additives. The facestocks are preferablypolyvinylchloride facestocks. The additives include plasticizers andantioxidants. The plasticizer is a high-boiling solvent or softeningagent, usually liquid. It is an ester made from an anhydride or acid anda suitable alcohol that usually has between 6 to 13 carbon atoms. Theplasticizers may be adipate, phosphate, benzoate or phthalate esters,polyalkylene oxides, sulfonamides, etc. The plasticizers include but arenot limited to DOA plasticizer (dioctyl adipate), TEG-EH plasticizer(triethylene glycol di-2-ethylhexanoate), TOTM plasticizer (trioctyltrimellitate), triacetin plasticizer (glyceryl triacetate), TXIBplasticizer (2,2,4-trimethyl-1,3-pentanediol diisobutyrate), DEPplasticizer (diethyl phthalate), DOTP plasticizer (dioctylterephthalate), DMP plasticizer (dimethyl phthalate), DOP plasticizer(dioctyl phthalate), DBP plasticizer (dibutyl phthalate), polyethyleneoxide, toluenesulfonamide, dipropylene glycol benzoate, and the like.

The adhesive articles have a continuous adhesive layer, typically apressure sensitive adhesive layer. In some applications, the adhesivemay be a heat activated adhesive, as distinguished from a pressuresensitive adhesive. The adhesive layer typically has a thickness fromabout 10 to about 125, or from about 25 to about 75, or from about 10 toabout 50 microns. In one embodiment, the coat weight of the pressuresensitive adhesive is in the range of about 10 to about 50 grams persquare meter (gsm), and in one embodiment about 20 to about 35 gsm. Thepressure-sensitive adhesive can be any pressure sensitive adhesive knownin the art. These include rubber based adhesives, acrylic adhesives,vinyl ether adhesives, silicone adhesives, and mixtures of two or morethereof. Included are the pressure sensitive adhesive materialsdescribed in “Adhesion and Bonding”, Encyclopedia of Polymer Science andEngineering, Vol. 1, pages 476-546, Interscience Publishers, 2nd Ed.1985, the disclosure of which is hereby incorporated by reference. Thepressure sensitive adhesive materials that are useful may contain as amajor constituent an adhesive polymer such as acrylic type polymers,block copolymers, natural, reclaimed or styrene butadiene rubbers,tackified natural or synthetic rubbers, random copolymers of ethyleneand vinyl acetate, ethylene-vinyl-acrylic terpolymers, polyisobutylene,poly(vinyl ether), etc. The pressure sensitive adhesive materials aretypically characterized by glass transition temperatures in the range ofabout −70° C. to about 10° C.

Other materials in addition to the foregoing resins may be included inthe pressure sensitive adhesive materials. These include solidtackifying resins, liquid tackifiers (often referred to asplasticizers), antioxidants, fillers, pigments, waxes, etc. The adhesivematerials may contain a blend of solid tackifying resins and liquidtackifying resins (or liquid plasticizers). Particularly usefuladhesives are described in U.S. Pat. Nos. 5,192,612 and 5,346,766 whichare incorporated herein by reference.

The pressure sensitive adhesive can be applied using standard coatingtechniques, such as curtain coating, gravure coating, reverse gravurecoating, offset gravure coating, roller coating, brushing, knife-overroll coating, air knife coating metering rod coating, reverse rollcoating, doctor knife coating, dipping, die coating, spraying, and thelike. The application of these coating techniques is well known in theindustry and can effectively be implemented by one skilled in the art.The knowledge and expertise of the manufacturing facility applying thecoating determine the preferred method. Further information on coatingmethods can be found in “Modern Coating and Drying Technology”, byEdward Cohen and Edgar Gutoff, VCH Publishers, Inc., 1992.

Release liners for use in the present invention may be those known inthe art. In general, useful release liners include polyethylene coatedpapers with a commercial silicone release coating, polyethylene coatedpolyethylene terephthalate films with a commercial silicone releasecoating, or cast polypropylene films that can be embossed with a patternor patterns while making such films, and thereafter coated with acommercial silicone release coating. A preferred release liner is kraftpaper which has a coating of low density polyethylene on the front sidewith a silicone release coating and a coating of high densitypolyethylene on the back side. Other release liners known in the art arealso suitable as long as they are selected for their releasecharacteristics relative to the pressure sensitive adhesive chosen foruse in the present invention. In one embodiment of the invention, therelease liner has a moldable layer of polymer under the release coating.The moldable layer is typically a polyolefin, such as polyethylene orpolypropylene. The surface of the release layer of the release liner mayhave a textured finish, a smooth finish, or a patterned finish. Therelease layer may have a randomly microstructured surface such as amatte finish, or have a pattern of three-dimensional microstructures.The microstructures may have a cross-section which is made up ofcircles, ovals, diamonds, squares, rectangles, triangles, polygons,lines or irregular shapes, when the cross-section is taken parallel tothe surface of the release surface.

In one embodiment, the release liner has a release coating on bothsides; one side having a release coating of a higher release value thanthe release coating of the other side.

In one embodiment, the adhesive layer of the articles has a Sheffieldroughness of at least about 10 or at least about 75, or at least about150. The adhesive layer may itself have the roughness or may be formedwhen the adhesive is coated onto a release liner. It is understood thatthe release liner may have a Sheffield roughness at least about 10 or atleast about 50, or at least about 75 or at least about 150. The adhesivewill replicate the complementary texture or pattern of the releaseliner. Alternatively, the release liner can be much rougher depending onthe configuration of the adhesive article. The Sheffield roughness isdetermined by TAPPI T 538 om-88.

Applicant has discovered that the addition of the non-adhesive materialeither on or in the adhesive layer provides improved air egress. Thenon-adhesive may be embedded so that its outer surface is even with theplane of the adhesive surface. Alternatively, the non-adhesive may beembedded so that its outer surface extends beyond the plane of theadhesive surface, or embedded so that its outer surface is below theplane of the adhesive surface (i.e., within the adhesive layer). Whenthe non-adhesive material is embedded to a level even with the plane ofthe adhesive layer, the non-adhesive material provides air egress alongthe interface. This is particularly true for the smaller bubbles whichform as the natural result of laying the adhesive construction onto asubstrate. Even when applied properly, small bubbles are still formed.The air in these bubbles needs a route to egress. The interface of thenon-adhesive material and the substrate is the area where this occurs.When the non-adhesive material extends beyond the adhesive layer, thenon-adhesive material provides repositionability and/or slideability aswell as air egress. This is of particular advantage when applyingadhesive articles to surfaces that are above room temperature. Theamount of the non-adhesive material extending below the adhesive layerneeds to be only sufficient to prevent contact of the adhesive layerwith the substrate.

The invention is further described by referring to the Figures.Referring to FIG. 1 a, article 10 has facestock 11 in adhesive contactwith adhesive layer 12. Adhesive layer 12 has embedded within itnon-adhesive material 13. Embedding may be carried out using pressureand/or heated rollers or a platen, whereby the non-adhesive material ispressed into the adhesive layer. Alternatively, the non-adhesivematerial is embedded into the adhesive layer by winding the article sothat the patterned lower surface of the adhesive is in contact with thefront (upper) surface of the facestock. The facestock may have a releasecoating on its front surface. It is understood that at least a majoramount of the non-adhesive material is embedded within adhesive layer12. Typically more that 75%, and more than 85% of the thickness of thenon-adhesive material 13 is embedded in the adhesive layer 12.

In referring to FIG. 1 b, the adhesive article 10 has the additionalelement of a release liner 14. The release liner 14 is in releasableadhesive contact with adhesive layer 12 and contacts non-adhesivematerial 13. The adhesive layer 12 is also in adhesive contact withfacestock 11. Embedding the non-adhesive material into the adhesivelayer may be carried out by applying the release liner to the adhesivelayer. The pressure used in applying the release liner embeds thenon-adhesive into the adhesive layer.

In another embodiment, the adhesive article comprises a first releaseliner in adhesive contact with an adhesive layer. The adhesive layer hasembedded into its exposed surface a pattern of non-adhesive material. Asecond release liner is applied to the patterned exposed adhesivesurface. The surface of the second release liner in contact with theadhesive layer may be textured. The texture may be a random texture or apatterned texture.

Referring to FIG. 2 a, article 20 has facestock 21, which is in adhesivecontact with adhesive layer 22. Adhesive layer 22 is in adhesive contactwith non-adhesive material 23 embedded in adhesive layer 22. Adhesivelayer 22 has a textured surface 24. In FIG. 2 b, the article has theadditional element of a release liner 25. The release liner 25 is inadhesive contact with adhesive layer 22 and in contact with thenon-adhesive material 23 embedded in adhesive layer 22. It should benoted that the release liner in the present invention may be textured.The textured surface of the adhesive layer may be produced during theembedding step. Alternatively, the texture in the release liner may betransferred to the adhesive layer during the adhesive coating process.Commercially available textured liners may be used.

In another embodiment, illustrated in FIG. 3 a, an adhesive article 30having improved air egress is provided by simultaneously printing andembedding a pattern of non-adhesive areas 33 into the surface of anadhesive 32 on a release liner 34. Using flexographic printingtechniques, a pattern, such as diamonds, is printed into the exposedsurface of an adhesive 32 on a release liner 34. The non-adhesivematerial 33 is a non-adhesive resin which upon drying, cooling, and/orcuring maintains its shape. The printing technique embeds the print intothe soft surface of the adhesive 32, leaving channels 35 with most ofthe printing compound on the bottom of the channels. Thus, the topsurface of the printing compound 33 is below the plane of the uppersurface of the adhesive layer 32. The non-adhesive material 33 is chosenfrom those materials that prevent the adhesive from flowing back intothe channels 35 created by the printing process. Examples of suchnon-adhesive materials include hard PMMA, or a two component urethane.Referring to FIG. 3 b, the printed adhesive 32 with channels 35 istransferred by lamination to a facestock 31, maintaining the channels inthe adhesive. Upon removal of the release liner 34 and application ofthe exposed adhesive to the surface of substrate 37 using pressure thechannels 35 collapse or partially collapse, forming voids 36 at theinterface between the adhesive 32 and the substrate 37, allowing trappedair to move to the exposed edges, as illustrated in FIG. 3 c.

In one embodiment of the present invention, the adhesive article isprepared by applying a non-adhesive material to the adhesive surface ofan adhesive article. The non-adhesive material may be fully or partiallyembedded into the adhesive surface. Embedding may be carried out usingpressure and/or heated rollers or a platen, whereby the non-adhesivematerial is pressed into the adhesive surface. The roller may be asilicone rubber roller. Embedding into the adhesive typically occurs ata temperature from about 65° to about 200° F., or from about 100° toabout 150° F. The embedding pressure for embedding into the adhesive istypically between about 15 to about 100 psi, or from about 25 to about50 psi. Alternatively, the non-adhesive material may be embedded intothe adhesive layer by applying with pressure another layer, such as arelease liner or facestock layer onto the non-adhesive patterned surfaceof the adhesive layer. The non-adhesive material may also be embeddedinto the adhesive layer by winding up the adhesive layer coated onto afacestock or release liner so that the non-adhesive material is embeddedinto the adhesive layer when the exposed surface of the adhesivecontacts the outer surface of the facestock or release liner. Thenon-adhesive material will generally be embedded at a level of at leastabout 50%, or at least about 75%, or at least about 85% of the thicknessof the non-adhesive material, or embedded to a level equal to thesurface of the embedding media.

In another embodiment of the present invention illustrated in FIGS. 4a-b, an adhesive article having improved air egress is provided bysimultaneously printing and embedding a pattern of non-adhesive areasinto the surface of an adhesive on a facestock. The non-adhesive areasmay be printed and embedded by flexographic printing techniques. Thefacestock may be, for example, cast or extruded vinyl. The non-adhesivematerial is a non-adhesive resin which upon drying, cooling, and/orcuring maintains its shape. Referring to FIG. 4 a, an article havingimproved air egress is provided by simultaneously printing and embeddinga pattern of non-adhesive areas 43 into the surface of an adhesive 42 ona facestock 41. The printing technique embeds the print into the softsurface of the adhesive 42, leaving channels 45 with most of theprinting compound on the bottom of the channels. The non-adhesivematerial is chosen from those materials that prevent the adhesive fromflowing back into the channels created by the printing process. Examplesof such non-adhesive materials include hard PMMA, or a two componenturethane. Referring to FIG. 4 b, a release liner 44 is laminated to theexposed printed surface of the adhesive 42, maintaining the channel 45in the adhesive 42. Upon removal of the release liner 44 and applicationof the exposed adhesive to a surface using pressure, the channel 45collapses or partially collapses, allowing trapped air to move to theexposed edges.

FIGS. 5 a-b illustrate another embodiment. An adhesive article havingimproved air egress characteristics as well as improved facestocksmoothness is provided by simultaneously printing and embedding apattern of non-adhesive material into an adhesive on a facestock. Thenon-adhesive material pattern may be printed and embedded by usingflexographic printing techniques. The non-adhesive material issubsequently foamed to form a porous non-adhesive. The porousnon-adhesive partially, completely, or overly fills the channels in theadhesive. Referring to FIG. 5 a, a pattern of non-adhesive material 53is printed into the exposed surface of an adhesive 52 on a facestock 51.The printing technique presses the non-adhesive material into the softsurface of the adhesive, leaving a pattern with most of the non-adhesivematerial on the bottom of the channel. The non-adhesive material 53 iscomprised of a resin which upon drying, cooling, and/or curing is foamedto partially, completely, or overly fill the channel forming a porousnon-adhesive. Referring to FIG. 5 b, the adhesive with the porousnon-adhesive channels is transferred by lamination to a release liner54. Upon removal of the release liner and application of the exposedadhesive to a substrate surface with pressure, the porous non-adhesivein the channel collapses slightly, allowing trapped air to move to theexposed edges. Removal of the application pressure allows the porousnon-adhesive to return to its original uncompressed shape, removingtexture from the surface of the facestock.

FIGS. 6 a-c illustrate another embodiment. An adhesive article havingimproved air egress, characteristics as well as improved facestocksmoothness is provided by simultaneously printing and embedding apattern of non-adhesive material into an adhesive on a release liner.The non-adhesive material pattern may be printed and embedded by usingflexographic printing techniques. The non-adhesive material issubsequently foamed to form a porous non-adhesive. The porousnon-adhesive partially, completely, or overly fills the channels in theadhesive. Referring to FIG. 6 a, a pattern of non-adhesive material 63is printed into the exposed surface of an adhesive 62 on a release liner64. The printing technique presses the non-adhesive material 63 into thesoft surface of the adhesive 62, leaving a pattern with most of thenon-adhesive material 63 on the bottom of the channel. The non-adhesivematerial 63 is comprised of a resin which upon drying, cooling, and/orcuring is foamed to partially or completely fill the channel. Referringto FIG. 6 b, the printed adhesive with the porous non-adhesive channelsis transferred by lamination to a facestock 61. Referring to FIG. 6 c,upon removal of the release liner 64 and application of the exposedadhesive 62 to a substrate surface 67 with pressure, the porousnon-adhesive 63 in the channel collapses slightly, forming voids 65 atthe interface between the adhesive 62 and the substrate 67, allowingtrapped air to move to the exposed edges. Removal of the applicationpressure allows the foamed print to return to its original uncompressedshape, removing texture from the surface of the facestock 61.

In another embodiment, a random pattern of non-adhesive particulates,such as for example, glass beads, can be applied to the surface of theadhesive layer and then partially or fully embedded into the adhesivelayer. The non-adhesive particulate, in addition to glass, may be madeof organic and inorganic particles, including but not limited topolymers, ceramics and metals. The non-adhesive particulate may bespherical, cubic, irregularly shaped, solid, porous, hollow, elastic orinelastic. Alternatively, the randomly distributed non-adhesiveparticulate material may be applied to and then partially or fullyembedded into the release liner.

In another embodiment, non-adhesive material is applied to and embeddedinto the upper surface of the adhesive layer. The release liner also hasa pattern of non-adhesive material printed thereon. The printednon-adhesive material may be embedded into the surface of the releaseliner prior to applying the adhesive onto the release liner. Uponremoval of the release liner from the adhesive, the non-adhesivematerial is transferred to the adhesive layer.

In yet another embodiment, non-adhesive material is applied to andembedded into the upper or lower surface of the adhesive layer. Therelease liner has randomly distributed non-adhesive particulate materialapplied to its release surface. The particulate non-adhesive materialmay be embedded into the surface of the release liner prior to applyingthe adhesive onto the release liner. Upon removal of the release linerfrom the adhesive, the non-adhesive material is transferred to theadhesive layer.

Another embodiment of the method of making the adhesive articles of thepresent invention includes the steps of: (a) applying a pattern of anon-adhesive material onto an adhesive layer that has been coated onto arelease liner; (b) embedding the non-adhesive material into the adhesivelayer; and (c) applying an additional release liner with a higher orlower release to the adhesive layer. The embedding and applying stepsmay be combined. The additional release liner may be omitted if theinitial release liner has a release means on both surfaces. Theseembodiment are commonly known as transfer adhesives or adhesivesandwiches.

Another embodiment of the method of making the adhesive articles of thepresent invention includes the steps of: (a) applying a pattern of anon-adhesive material onto an adhesive layer that has been coated ontothe back surface of a facestock; (b) embedding the non-adhesive materialinto the adhesive layer; and (c) winding the material so that theadhesive is in adhesive contact with the front surface of the facestock.The embedding and applying steps may be combined. A release means mayoptionally be added to the front surface of the facestock. Thisembodiment is commonly known as a linerless adhesive tape.

Another embodiment of the method of making the adhesive articles of thepresent invention includes the steps of: (a) applying a pattern of anon-adhesive material onto each of the outer surfaces of two adhesivelayers that have been coated onto the front and back surfaces of afacestock; (b) embedding the non-adhesive material into the adhesivelayers; and (c) applying a release liner with a release surfaces on eachof its two sides to the outer surface of one of the adhesive layers andwinding the material so that the outer surface of the second adhesivelayer is in adhesive contact with the second surface of the releaseliner. The embedding and applying steps may be combined. This embodimentis commonly known as a double faced adhesive tape.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. The features of the various embodiments of the adhesivearticles described herein may be combined into within an adhesivearticle. The various methods of manufacturing the adhesive articles ofthe present invention described herein may also be combined. Therefore,it is to be understood that the invention disclosed herein is intendedto cover such modifications as fall within the scope of the appendedclaims.

1. An adhesive article comprising: a release liner having a releasesurface and a back surface; a continuous layer of adhesive having anupper surface and a lower surface and end edges, wherein the uppersurface of the adhesive is adhered to the release surface of the releaseliner; and a pattern of non-adhesive material forms embedded into thelower surface of the adhesive layer, each of said non-adhesive materialforms having a bottom surface, wherein the bottom surfaces of thenon-adhesive material forms are above the plane of the lower surface ofthe adhesive layer.
 2. The adhesive article of claim 1 wherein thenon-adhesive material forms have an average thickness of about 30nanometers to about 100μ.
 3. The adhesive article of claim 1 wherein thepattern of non-adhesive material forms comprises a plurality of dots,lines or combinations thereof.
 4. The adhesive article of claim 3wherein the lines of non-adhesive material have an average width of fromabout 12 to about 250μ and an average thickness of from about 30nanometers to about 100μ.
 5. The adhesive article of claim 3 wherein atleast 50% of the lines intersect the end edges of the adhesive layer. 6.The adhesive article of claim 3 wherein the plurality of lines forms agrid pattern.
 7. The adhesive article of claim 1 wherein thenon-adhesive material at least comprises one of a porous non-adhesivematerial or an elastomer.
 8. The adhesive article of claim 1 furthercomprising a second release liner having a release surface, wherein saidrelease surface is applied to the lower surface of the adhesive layer.9. The adhesive article of claim 8 wherein the release surface of thesecond release liner has one of a textured surface, as random texture ora patterned finish.
 10. The adhesive article of claim 9 wherein thelower surface of the adhesive layer has a textured surface that iscomplementary to the textured surface of the second release liner. 11.The adhesive article of claim 1 wherein the back surface of the releaseliner has a release coating thereon, the release coating having a higherrelease value than that of the release surface.
 12. The adhesive articleof claim 1 wherein the release surface of the release liner has anon-adhesive material printed thereon.
 13. The adhesive article of claim12 wherein the non-adhesive material printed on the release surface ofthe release liner is embedded into the release surface.
 14. The adhesivearticle of claim 1 wherein the lower surface of the adhesive layer hasrandomly distributed non-adhesive particulate material embedded therein.